KR102558331B1 - Multi Band Base Station Antenna Using Selective Shield Surface - Google Patents

Abstract

A multi-band base station antenna using a selective shielding surface is disclosed. The disclosed antenna includes an optional shielding surface for passing signals of a preset frequency band; a plurality of low-band radiators positioned on the selective shielding surface; a reflector disposed under the selective shielding surface and spaced apart from the selective shielding surface; Including a plurality of high-band radiators coupled to the reflector. The selective shielding surface has a pass band set to pass a signal emitted from the high-band radiator and shield a signal emitted from the low-band radiator. According to the disclosed antenna, there is an advantage in that interference between a high-band radiator and a low-band radiator can be efficiently suppressed by using a selective shielding surface in a multi-band base station antenna for 5G in which beamforming is performed at various angles.

Description

Multi Band Base Station Antenna Using Selective Shield Surface

The present invention relates to a multi-band base station antenna, and more particularly, to a multi-band base station antenna using a selective shielding surface.

Currently, installation and demand for 5G communication systems are rapidly increasing, and methods for efficient use with the existing LTE communication network are being reviewed. The background of this technology being reviewed is that it costs a lot to install a new base station to operate a 5G communication system, and when a 5G communication system is installed in addition to a base station of an existing communication system, there is a problem that the quality of communication service is deteriorated due to interference between systems.

In order to operate efficient communication networks, existing antennas operate in multi-band and a technique for miniaturizing the size of the antenna is absolutely necessary. This technology is already being actively researched in the domestic and international antenna industry, but it is difficult to secure stable antenna performance in multiple bands and miniaturize the antenna.

In order to miniaturize a base station antenna, a plurality of radiators must be placed in a limited space, and to implement multi-band characteristics, antennas covering 698 to 960 MHz, 1427 to 2690 MHz, and 5G communication system bands (sub-6G, 3 GHz frequency band) must be arranged appropriately for the frequency used.

1 is a diagram showing a radiator arrangement structure of a conventional multi-band base station antenna for 5G.

Referring to FIG. 1 , a conventional multi-band base station antenna for 5G includes a plurality of low-band radiators 100 and a plurality of high-band radiators 110. The low-band radiator 100 and the high-band radiator 110 are arranged while sharing the same reflector (not shown), and such an arrangement structure inevitably causes interference between the high-band radiator and the low-band radiator.

An object of the present invention is to propose a multi-band base station antenna capable of effectively suppressing interference between a high-band radiator and a low-band radiator.

Another object of the present invention is to propose a multi-band base station antenna capable of suppressing interference between radiators of different bands by using a selective shielding surface in a multi-band base station antenna for 5G in which beamforming is performed at various angles.

According to one aspect of the present invention to achieve the above object, an optional shielding surface for passing signals of a preset frequency band; a plurality of low-band radiators positioned on the selective shielding surface; a reflector disposed under the selective shielding surface and spaced apart from the selective shielding surface; Including a plurality of high-band radiators coupled to the reflector. The selective shielding surface is provided with a multi-band base station antenna using a selective shielding surface in which a pass band is set to pass signals radiated from the high-band radiator and shield signals radiated from the low-band radiator.

The optional shielding surface has a structure in which unit cells are repeatedly arranged.

The unit cell includes a plurality of subcells, and the plurality of subcells included in the one unit cell have a mutually symmetrical relationship or have the same shape.

Each of the plurality of subcells includes a plurality of spiral arms.

The spiral arm of a specific subcell is connected to the spiral arm of another adjacent subcell.

The number of spiral arms of each of the plurality of subcells corresponds to the number of vertices of a polygon corresponding to the shape of the subcell.

Vertical selective shielding surfaces orthogonal to the selective shielding surface are coupled to both sides of the selective shielding surface, and the vertical selective shielding surface has a pass band set to pass signals emitted from the high-band radiator and shield signals emitted from the low-band radiator.

According to another aspect of the present invention, a selective shielding surface for passing signals of a preset frequency band; And a plurality of first radiators located on the selective shielding surface, wherein the selective shielding surface has a passband set to shield a radiation signal of the first radiator, and the selective shielding surface has a structure in which unit cells are repeatedly arranged. The unit cell includes a plurality of subcells, and a plurality of subcells included in one unit cell have a mutually symmetrical relationship or have the same shape. A multi-band base station antenna using a selective shielding surface is provided.

According to the present invention, there is an advantage in that interference between a high-band radiator and a low-band radiator can be efficiently suppressed by using a selective shielding surface in a multi-band base station antenna for 5G where beamforming is performed at various angles.

1 is a diagram showing a radiator arrangement structure of a conventional multi-band base station antenna for 5G.
2 is a perspective view of a multi-band base station antenna using a selective shielding surface according to an embodiment of the present invention.
3 is a cross-sectional view of a multi-band base station antenna using a selective shielding surface according to an embodiment of the present invention.
4 is a view showing the structure of a selective shielding surface according to an embodiment of the present invention.
5 is a view showing the structure of one unit cell in a selective shielding surface according to an embodiment of the present invention.
6 is a diagram showing the structure of one subcell in a selective shielding surface according to an embodiment of the present invention.
7 is a view showing a structure when the number of spiral arms is two when the overall shape of a subcell is a quadrangle;
8 is a graph showing characteristics of a selective shielding surface when the subcell shown in FIG. 7 is used.
9 is a graph showing characteristics of a selective shielding surface when the number of spiral arms is 4, as shown in FIG.
10 is a view for explaining size constraint conditions of unit cells constituting a selective shielding surface according to an embodiment of the present invention.
11 is a view showing the structure of a selective shielding surface according to another embodiment of the present invention.
12 is a view showing the structure of a selective shielding surface according to another embodiment of the present invention.
13 is a perspective view of a multi-band base station antenna using a selective shielding surface according to another embodiment of the present invention.
14 is a cross-sectional view of a multi-band base station antenna using a selective shielding surface according to another embodiment of the present invention.

In order to fully understand the present invention and its operational advantages and objectives achieved by the practice of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the described embodiments. And, in order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals in the drawings indicate the same members.

Throughout the specification, when a part "includes" a certain component, it means that it may further include other components, not excluding other components unless otherwise stated. In addition, terms such as “… unit”, “… unit”, “module”, and “block” described in the specification mean a unit that processes at least one function or operation, which can be implemented as hardware or software or a combination of hardware and software.

2 is a perspective view of a multi-band base station antenna using a selective shielding surface according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view of a multi-band base station antenna using a selective shielding surface according to an embodiment of the present invention.

2 and 3, a multi-band base station antenna according to an embodiment of the present invention may include a plurality of low-band radiators 200, a plurality of high-band radiators 300, a selective shielding surface 400, and a reflector 500.

The plurality of low-band radiators 200 are radiators configured to transmit and receive low-band signals. Since the size of the radiator is in inverse proportion to the radiating frequency band, the low-band radiator 200 has a larger size than the high-band radiator. The plurality of low-band radiators 200 are fixed to the upper portion of the optional shielding surface 400, and specifically, the low-band balun 210 for power feeding and impedance matching to the low-band radiator 200 is selective to the upper portion of the shielding surface 400. Can be fixed.

According to an embodiment of the present invention, the low-band radiator 200 may be a radiator set to radiate dual polarized signals of +45 degree polarization and -45 degree polarization, and may emit, for example, a band of 1 GHz or less.

The optional shielding surface 400 serves to selectively pass or shield RF signals according to frequencies. Specifically, the selective shielding surface 400 operates to pass signals of a preset frequency band and shield signals of frequencies other than the corresponding frequency band. The pass band of the selective shielding surface 400 is set to pass the radiation signal of the high-band radiator 300 and shield the radiation signal of the low-band radiator 200 .

Since the selective shielding surface 400 operates to shield the radiation signal of the low-band radiator 200, the selective shielding surface 400 functions as a reflector from the viewpoint of the low-band radiator 200. Since the selective shielding surface 400 functions as a reflector from a low-band frequency viewpoint, the signal emitted from the low-band radiator 200 is reflected by the selective shielding surface 400, and as a result, the signal emitted from the low-band radiator 200 is directed upward to the selective shielding surface 400.

Meanwhile, under the selective shielding surface 400 , a plurality of high-band radiators 300 are arranged spaced apart from the selective shielding surface 400 . The high-band radiator 300 is a radiator configured to transmit and receive a high-band signal. Since the size of the radiator is inversely proportional to the radiating frequency band, the high-band radiator 300 has a smaller size than the low-band radiator. Since high-band signals often require higher gain than low-band signals, the number of high-band radiators 300 is generally greater than that of low-band radiators 200 . However, the number of high-band radiators 300 is not limited to the examples shown in FIGS. 2 and 3 and may be set in various ways according to required characteristics.

According to an embodiment of the present invention, the high-band radiator 300 may be a radiator set to radiate dual polarized signals of +45 degree polarization and -45 degree polarization, and may radiate, for example, a band of 1 GHz or higher.

Reflectors 500 are positioned below the plurality of high-band radiators 300 , and the plurality of high-band radiators 300 are fixed to the top of the reflector 500 . The balun 310 of the high-band radiator is fixed to the top of the reflector 500 .

According to a preferred embodiment of the present invention, the passband of the selective shielding surface is set to pass the signal emitted from the high-band radiator 300 .

Since the selective shielding surface 400 passes signals emitted from the high-band radiator 300, the selective shielding surface 400 does not function as a shielding surface or a reflector from the viewpoint of the high-band radiator 300, and signals emitted from the high-band radiator 300 pass through the selective shielding surface 400, which means that the selective shielding surface 400 does not affect the radiation pattern of the high-band radiator 300.

On the other hand, since the reflector 500 is located under the high-band radiator 300, signals from the high-band radiator 300 are reflected by the reflector 500 toward the reflector 500. As a result, a radiation pattern is formed so that the signal emitted from the high-band radiator 300 faces upward of the reflector 500.

When the high-band radiator 300 and the low-band radiator 200 are positioned adjacent to each other, signals from the low-band radiator 200 are induced into the high-band radiator 300 and affect the radiation signal of the high-band radiator 300. It frequently occurs, and securing isolation between the high-band radiator 300 and the low-band radiator 200 is a very important characteristic required for a multi-band antenna.

In the present invention, the low-band radiator 200 is placed above the selective shielding surface 400 and the high-band radiator 300 is placed below the selective shielding surface 400, thereby blocking the signal of the low-band radiator 200 from being induced by the high-band radiator 300. The antenna structure of the present invention can provide better isolation characteristics than conventional multi-band antennas, and the radiation pattern of the high-band radiator 300 is not affected by the selective shielding surface 400.

4 is a view showing the structure of a selective shielding surface according to an embodiment of the present invention, and FIG. 5 is a view showing the structure of one unit cell in the selective shielding surface according to an embodiment of the present invention.

Referring to Figures 4 and 5, a plurality of unit cells are repeatedly formed on the selective shielding surface according to an embodiment of the present invention. It can be confirmed through FIG. 4 that the unit cell 600 as shown in FIG. 5 has a repeated structure.

A selective shielding surface that passes only a specific frequency band has been used for purposes such as selective absorption of electromagnetic waves. However, conventional selective shielding surfaces have not been used to isolate high-band signals and low-band signals as in the present invention, and conventional selective shielding surfaces cannot be used as reflectors that selectively function as in the present invention.

Signals emitted from the low-band radiator 200 or the high-band radiator 300 arrive at the selective shielding surface 400 at various angles, and the selective shielding surface 400 of the present invention needs to achieve the same effect for signals arriving at various angles. For example, it is necessary to maintain the same passband for signals arriving vertically (0 degrees) and signals arriving at 60 degrees. However, the conventional selective shielding surface 400 did not have the same passband for signals arriving at various angles, and for this reason, it was difficult to be used for isolating high-band signals and low-band signals, and selectively reflecting only low-band signals and selectively passing only high-band signals.

The present invention has a structure in which unit cells are repeatedly formed to maintain the same pass band for signals arriving at various angles.

Referring to FIG. 5 , a unit cell of a selective shielding surface according to an embodiment of the present invention may be divided into a plurality of subcells 600-1, 600-2, 600-3, and 600-4. 5 shows an example divided into four subcells, but the number of subcells may be appropriately set as needed.

A plurality of subcells included in the unit cell 600 may have the same shape or may have a symmetrical relationship with each other.

Referring to FIG. 5 , the first subcell 600-1 and the second subcell 600-2 have a horizontally symmetrical relationship, the first subcell 600-1 and the third subcell 600-3 have a symmetrical relationship at the origin, and the first subcell 600-1 and the fourth subcell 600-4 have a vertically symmetrical relationship. This is to have the same passband characteristics for signals incident at various angles.

6 is a diagram showing the structure of one subcell in a selective shielding surface according to an embodiment of the present invention.

Referring to FIG. 6 , a subcell according to an embodiment of the present invention includes a plurality of spiral arms 700, 710, 720, and 730 formed from a central point. The spiral arms 700, 710, 720, and 730 have a structure in which they are bent over a number of times while extending from a central point.

A subcell composed of a plurality of spiral arms has a polygonal structure as a whole, and FIG. 6 shows a subcell having a rectangular structure as a whole.

According to a preferred embodiment of the present invention, the spiral arms of each subcell are connected to the spiral arms of other adjacent subcells. The selective shielding surface 400 has a structure in which unit cells are repeatedly arranged while spiral arms of subcells are connected to spiral arms of other subcells.

According to a preferred embodiment of the present invention, the number of spiral arms constituting a subcell is related to the overall shape of the subcell. The number of spiral arms constituting the subcell corresponds to the number of vertices of the overall shape of the subcell.

Referring to FIG. 6 , the subcell has a rectangular shape as a whole, and thus the subcell is composed of four spiral arms. If the overall shape of the subcell is triangular, the subcell is preferably composed of three spiral arms.

7 is a diagram showing a structure when the number of spiral arms is two when the overall shape of a subcell is a rectangle, and FIG. 8 is a graph showing characteristics of a selective shielding surface when the subcell shown in FIG. 7 is used.

Referring to FIG. 7 , the overall shape of a subcell is a rectangle, but the number of spiral arms is two. When only two spiral arms are formed as shown in FIG. 7 , it is difficult to have uniform characteristics depending on the angle of a signal (beam) arriving at the selective shielding surface 400 .

In FIG. 8, the red solid line is the S11 graph of the selective shielding surface when the angle of the incoming beam is 0 degrees, the red dotted line is the S11 graph of the optional shielding surface when the angle of the incoming beam is 60 degrees, and the blue solid line is the S21 graph when the angle of the incoming beam is 0 degrees, and the blue dotted line is the S21 graph when the angle of the incoming beam is 60 degrees.

Referring to FIG. 8 , it can be seen that the pass band of the selective shielding surface is changed when the angle of the beam is changed. When the angle of arrival of the beam is 0 degrees, a band having a center frequency of 1.5 GHz is a pass band, or when an angle of arrival of a beam is 60 degrees, a band having a center frequency of 2.5 GHz is a pass band. Meanwhile, when the number of spiral arms is two, it can be seen that the loss also varies according to the angle of arrival of the beam.

8, when the number of spiral arms is two, uniform characteristics cannot be guaranteed according to the angle of arrival of the beam, and even when the number of spiral arms is three, uniform characteristics according to the angle of arrival of the beam cannot be guaranteed.

FIG. 9 is a graph showing characteristics of a selective shielding surface when the number of spiral arms is four as shown in FIG. 5 .

In FIG. 9, the red solid line is the S11 graph of the selective shielding surface when the angle of the incoming beam is 0 degrees, the red dotted line is the S11 graph of the optional shielding surface when the angle of the incoming beam is 60 degrees, and the blue solid line is the S21 graph when the angle of the incoming beam is 0 degrees, and the blue dotted line is the S21 graph when the angle of the incoming beam is 60 degrees.

Referring to FIG. 9 , when the number of spiral arms is 4, it can be seen that the passband is maintained the same according to the angle of arrival of the beam. In addition, it can be seen that S21 representing the loss also remains the same.

10 is a diagram for explaining size constraint conditions of unit cells constituting a selective shielding surface according to an embodiment of the present invention.

Referring to FIG. 10, the unit cell width W may be set to 0.132λ. In addition, the total length (L1 + L2 * 2 + L3 * 2 + L4 * 2) of the spiral arms connected to each other may be set to 0.25λ. Meanwhile, the width of the spiral arms may be set to 0.002λ to 0.004λ, and the interval between the spiral arms may be set to 0.002λ to 0.006λ.

The size information described with reference to FIG. 10 may be exemplary, and it will be apparent to those skilled in the art that the size information may vary depending on the environment in which the selective shielding surface 400 is installed and the frequency of use.

11 is a view showing the structure of a selective shielding surface according to another embodiment of the present invention.

Referring to FIG. 11, a shielding surface in which hexagonal unit cells are repeatedly arranged is shown. A hexagonal unit cell is composed of 6 subcells, and each subcell has a triangular shape as a whole. Spiral arms constituting each subcell are connected to spiral arms of other adjacent subcells.

Since the overall shape of the subcell is a triangle, the number of spiral arms constituting each subcell is three.

12 is a view showing the structure of a selective shielding surface according to another embodiment of the present invention.

The selective shielding surface shown in FIG. 12 also has a structure in which hexagonal unit cells are repeatedly arranged, and each subcell constituting the unit cell has a triangular shape as a whole. Compared to FIG. 11, the shape of the spiral arm is different and the number of spiral arms is the same.

13 is a perspective view of a multi-band base station antenna using a selective shielding surface according to another embodiment of the present invention, and FIG. 14 is a cross-sectional view of a multi-band base station antenna using a selective shielding surface according to another embodiment of the present invention.

In the embodiment shown in FIGS. 13 and 14 , vertical optional shielding surfaces 410 - 1 and 410 - 2 are coupled to both sides of the optional shielding surface 400 when compared to the embodiment shown in FIGS. 2 and 3 . The vertical selective shielding surfaces 410-1 and 410-2 also operate to pass signals of a preset band and shield signals other than the corresponding frequency band, and the vertical selective shielding surfaces 410-1 and 410-2 function as a choke member for the low-band radiator 200. The choke member is formed perpendicularly to the reflector and is used to improve isolation between radiators and to control beam width.

Since signals emitted from the low-band radiator 200 are reflected from the vertical selective shielding surfaces 410-1 and 410-2, the vertical selective shielding surfaces 410-1 and 410-2 can function as choke members for the low-band radiator 200. Since signals emitted from the high-band radiator 300 pass through the vertical selective shielding surfaces 410-1 and 410-2, the signals emitted from the high-band radiator 300 are not affected. In addition, slots 410-3 and 410-4 are formed on the vertical selective shielding surface to improve the front-to-rear ratio of the low-band radiator 200.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is only exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

Claims (15)

an optional shielding surface that passes signals of a preset frequency band;
a plurality of low-band radiators positioned on the selective shielding surface;
a reflector disposed under the selective shielding surface and spaced apart from the selective shielding surface;
Including a plurality of high-band radiators coupled to the reflector.
The multi-band base station antenna using the selective shielding surface, characterized in that the pass band is set so that the selective shielding surface passes the signal radiated from the high-band radiator and shields the signal radiated from the low-band radiator.
According to claim 1,
The selective shielding surface is a multi-band base station antenna using a selective shielding surface, characterized in that it has a structure in which unit cells are repeatedly arranged.
According to claim 2,
The unit cell includes a plurality of subcells, and the plurality of subcells included in the one unit cell have a mutually symmetrical relationship or have the same shape.
According to claim 3,
A multi-band base station antenna using a selective shielding surface, characterized in that each of the plurality of subcells includes a plurality of spiral arms.
According to claim 4,
A multi-band base station antenna using a selective shielding surface, characterized in that the spiral arm of a specific subcell is connected to the spiral arm of another adjacent subcell.
According to claim 4,
The multi-band base station antenna using a selective shielding surface, characterized in that the number of spiral arms of each of the plurality of subcells corresponds to the number of vertices of a polygon corresponding to the shape of the subcell.
According to claim 1,
Vertical selective shielding surfaces orthogonal to the selective shielding surface are coupled to both sides of the selective shielding surface, and the vertical selective shielding surface has a pass band set to pass signals emitted from the high-band radiator and shield signals emitted from the low-band radiator.
an optional shielding surface that passes signals of a preset frequency band;
a plurality of first radiators positioned above the selective shielding surface; and
Including a plurality of second radiators located below the selective shielding surface,
The selective shielding surface has a pass band set to shield a radiation signal of the first radiator,
The selective shielding surface has a structure in which unit cells are repeatedly arranged,
The unit cell includes a plurality of subcells, and the plurality of subcells included in the one unit cell have a mutually symmetrical relationship or have the same shape.
delete According to claim 8,
The selective shielding surface is a multi-band base station antenna using a selective shielding surface, characterized in that a pass band is set to pass the signal emitted from the second radiator
According to claim 8,
A multi-band base station antenna using a selective shielding surface, characterized in that each of the plurality of subcells includes a plurality of spiral arms.
According to claim 11,
A multi-band base station antenna using a selective shielding surface, characterized in that the spiral arm of a specific subcell is connected to the spiral arm of another adjacent subcell.
According to claim 11,
The multi-band base station antenna using a selective shielding surface, characterized in that the number of spiral arms of each of the plurality of subcells corresponds to the number of vertices of a polygon corresponding to the shape of the subcell.
According to claim 10,
A vertical selective shielding surface orthogonal to the selective shielding surface is coupled to both sides of the selective shielding surface, and the vertical selective shielding surface passes a signal emitted from the second radiator and a pass band is set to shield a signal emitted from the first radiator.
According to claim 14,
A multi-band base station antenna using a selective shielding surface, characterized in that a slot is formed on the vertical selective shielding surface